In an electrolytic cell, the electrolyte often undergoes chemical changes as the electrolysis process progresses. Depending on the type of electrolyte and the reactions occurring at the electrodes, the concentration of the electrolyte may change, or the electrolyte itself may be consumed or transformed into another compound. For instance, in the electrolysis of water, the water acts as the electrolyte and is decomposed into oxygen and hydrogen gases, resulting in a decrease in the volume of the electrolyte over time. It's crucial to monitor and replace or replenish the electrolyte when necessary to ensure the efficient functioning of the cell.

Lithium is a preferred element for use in modern rechargeable batteries due to its numerous advantageous properties. Firstly, lithium is the lightest metal, which allows for lightweight battery designs. Secondly, it has a very high electrochemical potential, meaning it can result in higher voltages compared to other materials. This makes lithium-ion batteries able to store and deliver a significant amount of energy relative to their size. Additionally, they have a longer lifecycle, can hold their charge well (low self-discharge rate), and don't suffer from a memory effect, which can plague some other types of rechargeable batteries.

No, secondary cells, even though they are rechargeable, cannot last indefinitely. Each time a cell undergoes a charge-discharge cycle, tiny structural and chemical changes occur inside the battery, which may lead to reduced efficiency and capacity. Over time, after numerous charge-discharge cycles, the battery's ability to hold and deliver charge diminishes. Factors like deep discharges, overcharging, high temperatures, and internal short circuits can accelerate this degradation. The term "cycle life" refers to the number of complete charge-discharge cycles a battery can undergo before its capacity drops below a specified percentage of its initial capacity.

The salt bridge in an electrochemical cell plays a crucial role in maintaining electrical neutrality within the internal cell environment. As redox reactions proceed at the electrodes, cations and anions are formed, which can disrupt the neutrality of the solutions. The salt bridge contains a gel or porous paper soaked in an electrolyte, which allows for the movement of ions between the two half-cells. This ionic movement compensates for the charge imbalance that arises due to electron flow in the external circuit. Without a salt bridge or a similar setup, the cell's potential would rapidly decrease, stopping the electron flow.

Secondary cells are termed 'rechargeable' because they have the capacity to undergo multiple charge and discharge cycles. Unlike primary cells, which can only be used once and then must be discarded, secondary cells can be recharged when their stored energy is depleted. This is achieved through an external voltage source that forces the electrochemical reactions to proceed in the opposite direction, essentially 'refilling' the cell with energy. This ability to reverse the chemical reactions allows for extended usage, making secondary cells more sustainable and cost-effective in many applications compared to primary cells.